本文介绍了教义2获取没有关系的对象的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
用户只有一个角色。 一个角色有零个或多个用户。
An user has one role. A role has zero or many users.
我想查找没有用户的角色。
I would like to find roles without users.
我需要使用不使用IN或NOT IN 的查询
I need to have this query without using IN or NOT IN
我尝试使用join:
$qb = $this->createQueryBuilder('role'); $qb ->leftJoin('role.users', 'users') ->where('users IS NULL')不加入
$qb = $this->createQueryBuilder('role'); $qb ->where('role.users IS NULL')id:
$qb = $this->createQueryBuilder('role'); $qb ->leftJoin('role.users', 'users') ->where('users.role != role')您还有其他想法吗?除了使用IN / NOT IN查询,我别无选择吗?
Do you have other ideas? Do I have no other choices than to use IN / NOT IN queries?
预先感谢
推荐答案您可以使用计数查询来查找没有任何用户的角色
You can find roles that don't have any users by using a count query
$qb = $this->createQueryBuilder('role'); $qb ->addSelect('COUNT(users.id) AS total_users') ->leftJoin('role.users', 'users') ->groupBy('role.id') ->having('total_users = 0') ->getQuery()->getResult();更多推荐
教义2获取没有关系的对象
发布评论